Abstract
Summary Increased atmospheric carbon dioxide supply is predicted to alter plant growth and biomass allocation patterns. It is not clear whether changes in biomass allocation reflect optimal partitioning or whether they are a direct effect of increased growth rates. Plasticity in growth and biomass allocation patterns was investigated at two concentrations of CO 2 ([CO 2 ]) and at limiting and nonlimiting nutrient levels for four fast‐ growing old‐field annual species. Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicum were grown from seed in controlled growth chamber conditions at current (350 μmol mol −1 , ambient) and future‐ predicted (700 μmol mol −1 , elevated) CO 2 levels. Frequent harvests were used to determine growth and biomass allocation responses of these plants throughout vegetative development. Under nonlimiting nutrient conditions, whole plant growth was increased greatly under elevated [CO 2 ] for three C3 species and moderately increased for a C4 species ( Amaranthus ). No significant increases in whole plant growth were observed under limiting nutrient conditions. Plants grown in elevated [CO 2 ] had lower or unchanged root:shoot ratios, contrary to what would be expected by optimal partitioning theory. These differences disappeared when allometric plots of the same data were analysed, indicating that CO 2 ‐induced differences in root:shoot allocation were a consequence of accelerated growth and development rates. Allocation to leaf area was unaffected by atmospheric [CO 2 ] for these species. The general lack of biomass allocation responses to [CO 2 ] availability is in stark contrast with known responses of these species to light and nutrient gradients. We conclude that biomass allocation responses to elevated atmospheric [CO 2 ] are not consistent with optimal partitioning predictions.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
Under nonlimiting nutrients, elevated CO2 greatly increased whole-plant growth in three C3 species.
Verbatim
e1“Under nonlimiting nutrient conditions, whole plant growth was increased greatly under elevated [CO 2 ] for three C3 species and moderately increased for a C4 species ( Amaranthus )”
e2“at current (350 μmol mol −1 , ambient) and future‐ predicted (700 μmol mol −1 , elevated) CO 2 levels”
e3“Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicum were grown from seed in controlled growth chamber conditions”
Claim · model-written summary
Under nonlimiting nutrients, elevated CO2 moderately increased whole-plant growth in the C4 species Amaranthus.
- Taxon
- Amaranthus
_with_green_foliage%2C_photographed_in_Tamil_Nadu%2C_India.jpg?width=60)
Amaranthuse1 - Treatment
- elevated [CO 2 ]e1
- Outcome
- whole plant growthe1
- Direction
- moderately increasede1
- Qualifier
- Under nonlimiting nutrient conditionse1
- Comparator
- current (350 μmol mol −1 , ambient)e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_with_green_foliage%2C_photographed_in_Tamil_Nadu%2C_India.jpg?width=500)
Verbatim
e1“Under nonlimiting nutrient conditions, whole plant growth was increased greatly under elevated [CO 2 ] for three C3 species and moderately increased for a C4 species ( Amaranthus )”
e2“at current (350 μmol mol −1 , ambient) and future‐ predicted (700 μmol mol −1 , elevated) CO 2 levels”
Claim · model-written summary
Under limiting nutrients, whole-plant growth did not increase significantly with elevated CO2.
- Taxon
- Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicum
Chenopodium album
Abutilon theophrasti
Amaranthus retroflexus_(21143913879).jpg?width=60)
Persicaria pensylvanicae3 - Treatment
- limiting nutrient conditionse4
- Outcome
- whole plant growthe4
- Direction
- No significant increasese4
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_(21143913879).jpg?width=500)
Verbatim
e4“No significant increases in whole plant growth were observed under limiting nutrient conditions”
e3“Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicum were grown from seed in controlled growth chamber conditions”
Claim · model-written summary
Elevated CO2 gave lower or unchanged root:shoot ratios, contrary to optimal partitioning theory.
- Taxon
- Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicumChenopodium albumAbutilon theophrastiAmaranthus retroflexusPersicaria pensylvanicae3
- Treatment
- elevated [CO 2 ]e5
- Outcome
- root:shoot ratiose5
- Direction
- lower or unchangede5
- Qualifier
- contrary to what would be expected by optimal partitioning theorye5
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“Plants grown in elevated [CO 2 ] had lower or unchanged root:shoot ratios, contrary to what would be expected by optimal partitioning theory”
e3“Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicum were grown from seed in controlled growth chamber conditions”
Claim · model-written summary
Differences in root:shoot allocation disappeared when allometric plots of the same data were analysed.
- Taxon
- Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicumChenopodium albumAbutilon theophrastiAmaranthus retroflexusPersicaria pensylvanicae3
- Outcome
- differences in root:shoot allocatione6
- Qualifier
- disappeared when allometric plots of the same data were analysede6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“These differences disappeared when allometric plots of the same data were analysed, indicating that CO 2 ‐induced differences in root:shoot allocation were a consequence of accelerated growth and development rates”
e3“Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicum were grown from seed in controlled growth chamber conditions”
Claim · model-written summary
The CO2-induced root:shoot differences are suggested to be a consequence of accelerated growth and development rates.
- Taxon
- Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicumChenopodium albumAbutilon theophrastiAmaranthus retroflexusPersicaria pensylvanicae3
- Outcome
- differences in root:shoot allocatione6
- Qualifier
- a consequence of accelerated growth and development ratese6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e6“These differences disappeared when allometric plots of the same data were analysed, indicating that CO 2 ‐induced differences in root:shoot allocation were a consequence of accelerated growth and development rates”
e3“Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicum were grown from seed in controlled growth chamber conditions”
Claim · model-written summary
Elevated atmospheric CO2 did not change allocation to leaf area in these species.
- Taxon
- Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicumChenopodium albumAbutilon theophrastiAmaranthus retroflexusPersicaria pensylvanicae3
- Treatment
- atmospheric [CO 2 ]e7
- Outcome
- Allocation to leaf areae7
- Direction
- unaffectede7
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“Allocation to leaf area was unaffected by atmospheric [CO 2 ] for these species”
e3“Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicum were grown from seed in controlled growth chamber conditions”
Claim · model-written summary
Biomass allocation showed a general lack of response to CO2 availability, in contrast with known responses to light and nutrient gradients.
- Taxon
- Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicumChenopodium albumAbutilon theophrastiAmaranthus retroflexusPersicaria pensylvanicae3
- Outcome
- biomass allocation responses to [CO 2 ] availabilitye1
- Qualifier
- in stark contrast with known responses of these species to light and nutrient gradientse1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“The general lack of biomass allocation responses to [CO 2 ] availability is in stark contrast with known responses of these species to light and nutrient gradients”
e3“Abutilon theophrasti , Amaranthus retroflexus , Chenopodium album , and Polygonum pensylvanicum were grown from seed in controlled growth chamber conditions”
The same questions in other papers
co2 · growth · Chenopodium album (common lambsquarters)Positive and negative results
4 in the opposite direction
- positive
- positive
- positive
1 paper more in this group
See all 5 papers →co2 · growth · Abutilon theophrasti (velvetleaf)Positive and negative results
1 paper in the same direction as this paper · 4 in the opposite direction
- positive
- positive
- positive
2 papers more in this group
See all 6 papers →co2 · growth · Amaranthus retroflexus (redroot amaranth)Positive and negative results
4 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- no effect
3 papers more in this group
See all 7 papers →co2 · growth · AmaranthusResults agree
2 papers in the same direction as this paper
- positive
- positive
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.